In U.S. Pat. No. 3,017,717, Caubre describes a container for an open bottle of ant poison that is accessible to ants but that cannot be opened by a child. The container is a box with a hinged side wall. A steel pin extends through a bore in a top wall of the box and into an elongate recess in a lug attached to the inside of the hinged side wall, thereby locking the box closed. Since the pin does not protrude from the bore, it cannot be removed by hand, but must instead be drawn out by a magnet in order to unlock the box. Small holes in an end wall of the box give ants ready access to the open bottle of poisonous bait inside the box. Presumably, the poison should be sufficiently viscous to avoid leakage from the bottle through the ant access holes if up-ended by a child.
In U.S. Pat. No. 5,033,229, Demarest et al. describe a liquid bait station for roaches. The bait station has a base structure that includes a central well area with an absorbent pad and a plurality of insect access openings in side walls surrounding the well area. The bait station also has a funnel-shaped reservoir seated in the base structure and tapering to a narrow opening at its bottom for controllably releasing liquid bait onto the absorbent pad in the central well area. The larger upper end of the funnel-shaped reservoir has a cover.
In U.S. Pat. No. 5,548,922, Wefler describes an insect liquid bait station that includes a base having a floor and a peripheral dike that together define a reservoir for a slow-kill liquid insecticide. A porous pad sits in the pooled liquid on the floor of the reservoir. A cover is mounted in liquid-tight relation on the base. The cover has an inclined ramp leading down to a central stage area with access portals through which the target insects can enter and feed on the poisonous liquid on the porous pad. The tight mounting of the cover to the base and the use of a porous pad immediately beneath the access ports resist spillage of the liquid bait.
In U.S. Pat. No. 794,323, Small describes a poison vault for rodents which is constructed so that the poison bait is accessible to mice and rats, but not to fowl and larger animals, and also so that the rodents cannot carry away any large pieces of the bait. The vault includes an outer box with a hinged top. The outer box has round openings at an upper portion of each side and end wall, large enough to admit rats and mice, and at a height from the bottom so that the rodents must stand on their hind feet to pass through the opening. The vault also includes an inner box with side and end walls secured to the bottom of the outer box (but no lid) and separated from the outer walls to create a space between the inner and outer walls into which the rodents must first enter before passing through similar openings in the walls of the inner box. Because the rodents must stand on their hind feet to traverse the openings, they are unable to carry large pieces of bait with their feet and must leave the pieces behind or consume them while in the box. The hinged top of the outer box may be provided with a hook that engages a pin to securely close the box.
U.S. Pat. Nos. 4,026,064; 4,550,525; 5,040,327; 5,272,832; and 5,448,852 disclose other rodent bait stations. In general, these consist of a protective box provided with access holes, interior rooms or trays containing solid bait, and passageways from the holes to the rooms or trays. Bolts, ties or other means may be used to provide tamper resistant closure of these boxes. J.T. Eaton & Co., Inc. of Twinsbury, Ohio provides several models of rodent bait stations that use bait holding rods or racks in interior rooms, where the bait is in the form of blocks that can be slid onto the rod.
U.S. Pat. No. 1,964,611 to Watson discloses a combined rodent and insect exterminator station with separate compartments for solid rodent bait and liquid insect bait within an enclosed structure. The structure has openings that allow entry of rodents but that keep out chickens. The insect bait appears not to be sufficiently isolated from the rodent feeding compartments, so that mice or rats would have to traverse or pass by the insect bait area to reach the rodent bait. Rodents would be unlikely to feed in the presence of large numbers of ants.
An object of the invention is to provide a liquid bait station for ants or other crawling insects constructed to resist spillage of bait within the bait station.
Another object of the invention is to provide a liquid bait station with improved access to liquid bait by the target crawling insects.
Still another object of the invention is to provide a liquid bait station which is tamper resistant.
Another object of the invention is to provide a combined bait station with liquid bait for ants and solid bait for rodents, wherein rodents will feel comfortable feeding even when ants are also feeding in their own bait.